Method of making an electrical connector



Feb. 25, 1969 R, A, PATTON JR 3,429,041

METHOD OF MAKING AN ELECTRICAL CONNECTOR Filed July 5l, 1954 INVENTORROY A. PATTON, Jr.

MM, mi w ATTORNEYS Feb 25, 1969 R. A. PATToN, JR 3,429,041

METHOD OF MAKING AN ELECTRICAL CONNECTOR Filed July 3l, 1964 Sheei'I 2ROY A. PATTON, Jr.

AFTORNEYS Feb. 25, 1969 R, A, PATTON, JR 3,429,041

METHOD OF MAKING AN ELEOTR'OAL CONNECTOR Filed July 31, 1964 sheet 3 ofs INVENTOR ROY A. PATTON, Jr.

SYM

ATTORNEYS United States Patent O 3,429,041 METHD F IVIAKING ANELECTRICAL CNNECTOR Roy A. Patton, Ir., 6030 N. Shore Drive, Grabill,Ind. 46741 Filed July 31, 1964, Ser. No. 386,649 U.S. Cl. 29-629 15Claims Int. Cl. HZg 15/08; H01r 43/06; B29f l/IO ABSTRACT 0F THEDISCLQSURE A method of fabricating electrical connector parts comprisingthe steps of extruding a rod of insulating material having passagestherein, cutting the rod to certain lengths, and turning at least one ofthe ends of said rod to form steps in relation to said passages.

The present invention relates to an electrical connector, and moreparticularly to a multiple circuit connector composed of plug and socketparts which may be detachably connected together.

The development of miniaturized and microminiaturized electronicequipment has, as a matter of necessity, forced the development ofminiaturized components such as capacitors, transistors, inductors,connectors and the like. As a result of this miniaturizing, re-design ofthese components has been required, and in some instances suchre-designed, miniaturized components have suffered a considerable lossin reliability. While such components quite frequently constitute only asmall part of a much larger piece of equipment or system, the failure ofthe part many times can produce failure of the system. Further, problemshave been encountered in miniaturizing connectors so as to fit them intothe space limitations permitted by miniaturized electronic or electricalequipment. It has been found that such miniaturized connectors areespecially a constant source of trouble and equipment failure.

It is therefore an object of this invention to provide an electricalconnector and a method for fabricating the same which is extremely smallin size yet reliable, durable and efficient in use and relativelyinexpensive to manufacture.

It is another object of this invention to provide an electricalconnector wherein a maximum number of circuits can be completed in aminimum amount of space.

It is yet another object of this invention to provide a multiple circuitconnector having miniature and microminiature contact elements which arereplaceable whenever they become defective.

Other objects will become apparent as the description proceeds.

The above-mentioned and other features and objects of this invention andthe manner of attaining them will become more apparent and the inventionitself will be best understood by reference to the following descriptionof an embodiment of the invention taken in conjunction with theaccompanying drawings, wherein:

FIG. l is a fragmentary side view showing the male and female couplingelements of the electrical connector of this invention in disconnection;

FIGS. 2a and 2b are side views of the male and female coupling elementsof the electrical connector of FIG. 1 prior to the connection of wiresto the terminal ends;

FIG. 3 is a contact end view of the female coupling portion of theelectrical connector of this invention taken substantially along thesection line 3 3 of FIG. 2b;

FIG. 4 is a perspective View of the male connector element of thisinvention shown in side elevation in FIG. 2a;

FIG. 5 is an axial, sectional View of the coupling elements of FIGS. 2aand 2b shown in mating relationship;

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FIG. 6 is an enlarged fragmentary, sectional View of the male couplingelement of the electrical connector of this invention illustrating thedetent configuration of the distal end of the connectors and thestructure allowing the connectors to flex in a radial direction;

FIG. 7 is a perspective view of the male. coupling element of a secondembodiment of the electrical coupling of this invention;

FIG. 8 is a side view, in cross-section, of the female coupling elementof the second embodiment of the electrical connector of this invention;

FIG. 9 is a perspective view of an extruded rod segment which isfabricated during the performance of both of the methods of thisinvention;

FIG. 10 is a perspective view of the connectors used in the manufactureof the second embodiment of the male coupling element of this inventionshown in FIG. 7;

FIG. 11 is a perspective view of the electrical connectors used in themanufacture of the second embodiment of the female coupling element ofthis invention shown in FIG. 8;

FIG. 12 isa fragmentary side view, partly in cross-section, of anapparatus for performing a method for fabricating the first embodimentof the electrical connector of this invention;

FIG. 13 is a sectional view of the apparatus of FIG. l2 takensubstantially along the section line 13-13;

FIG. 14 is a fragmentary side view, partly in cross-sec` tion of anapparatus for performing a method of fabricating the second embodimentof the electrical connector of this invention; and

FIG. 15 is a cross-sectional view of the apparatus shown in FIG. 14taken substantially along section line 15-15.

In the broader aspects of this invention, an electrical connector isprovided comprising a substantially rigid body of insulated materialhaving a plurality of axially extending elongated conductor elementssecured in the body by a lock means. The conductor elements are exposedat both ends of the body, and at one end are capable of flexing radiallyinwardly ofsaid body.

Referring to the drawings, and more particularly to FIGS. l through 6,an electrical connector indicated generally by the numeral 20 iscomposed of two parts, a male coupling element 22 and a female couplingelement 24. These two parts are constructed almost identically such thata description of one will substantially suffice for the description ofthe other.

In the main, the connector is composed essentially of a cylindricallyshaped body 23 of insulating material. This material is preferablyplastic and may be a thermoplastic, thermosetting or of a solventsoluble type. Specifically, Mylar, Teflon, polyethylene, vinyl,Bakelite, phenolics and the like are satisfactory. Whatever material maybe used, the body 23 should be relatively rigid and should not deformunder localized pressure or deform as does soft rubber. When compared tothe metallic contact elements which will be described later, the bodymaterial may be regarded as rigid and non-flexible. Body 23 of male andfemale coupling elements 22, 24 has opposite ends 28, 30, matingportions 32, 34 adjacent ends 28, respectively, and terminal portions 36adjacent end 30. Elements 22, 24 have a plurality of axially extendingpassageways 26 which communicate with ends 23, 30. Passageways 26 arearranged in a plurality of coaxial and circular sets which arecircumferentially and equally spaced-apart from each other. Eachpassageway 26 is identical in cross-sectional size and shape and inlength. In the specific embodiment illustrated, passageways 26 are shownto be rectangular in cross-section; however, it is within the scope ofthis invention for passageways 26 to be square, round or other shapes.Terminal portion 36 has a number of integral, coaxial and differentdiametered step portions equal in number to the coaxial sets in whichthe passageways 26 are arranged. In the specific constructionillustrated two coaxial sets are shown and two step portions 38, 40comprise portion 36; however, it is within the scope of this inventionto have any number of sets and potrions. Axially extending passageways26 communicate with the surfaces of portions 38, 40 forming a pluralityof axially extending grooves which communicate with the distal ends 30,39 of portions 38, 40, respectively. Portion 40 has a diameter which issmaller than portion 38 and extends axially outwardly beyond portion 38so as to have a portion of grooves 42 in each of the portions 38, 4dwhich are exposed.

Referring now to portion 32 adjacent end 28 of male coupling element 22,there are illustrated two step portions 44, 46 which like step portions38, 4@ are coaxial, integral, and lof cylindrical shape. Portion 44,which has the smallest diameter, axially extends beyond the portion 46.Portions 44, 46 also have the longitudinal grooves 42 extending theiraxial length and communicating with the distal ends 28, 48 of theportions 44, 46, respectively.

In each of the passageways 26 of the male coupling element 22 issecurely fitted a straight, elongated conductor indicated generally bythe numeral 50. This conductor S has a cross-section of substantiallythe same size and shape as the passageway 26. Conductors 50 havesubstantially the same length as the combined length of the grooves 42and passageways 26 extending from distal end 428 to the distal end 38 ofportions 40, 44 respectively, and from the,

distal end 48 of portion 46 to the distal end of portion 38,respectively. Conductors 50 are of some suitable conductive metal,examples being bronze, brass, copper, aluminum, gold, silver, platinumor alloys thereof. A particularly useful material is beryllium copper.As will appear from the following description, it is desirable for theseelements S0 to be resilient and in this respect to correspond to barsprings.

The construction thus far described is of stepped diameteredconfiguration at the opposite ends as clearly shown in FIG. 2a. Asabove-described, end portion 32 may be regarded as the coupling or plugend, while the opposite end may be considered as the terminal end. Atboth ends, each of the conductors has an exterior surface which isexposed, equal in length to the exposed portion of the grooves 42 abovementioned. At the terminal end, this permits easy attachment, such as bysoldering, welding or crimping of wires to the terminal ends of each ofthe conductors 50. This is particularly important in the case in whichthe connector is extremely small in diameter. As the terminal ends ofthe conductors are circumferentially and equally spaced apart as are thepassageways 26, wires may be attached to the conductors 50 with aminimal chance of short circuit. The attachment of the wires to theterminal ends of the conductors is illustrated in FIG. l.

At the plug end (FIG. 4), the opposite ends of the conductors 50 areembedded in the grooves 42 of the step portions 44, 46 and have theirouter surfaces exposed the entire length of the aforesaid step portions.In some cases, it is desirable that the conductors 50 be raised slightlyabove the surface of the step portions 44, 46 for the reasons which willbecome apparent from the following description.

Adjacent the distal ends 28, 48, the portions 44, 46 and the conductorsS0 are formed with detent shapes. In axial section, (see FIG. 6) thesurface of the step portions 44, 46 is smoothly undulating with a crest52 being adjacent to the ends 28, 48 and a valley 54 being rearwardlythereof. The conductors 50 have a shape which is identical in allrespects to the shape of the surface of the step portions 44, 46.Immediately beneath the distal end `56 of the conductor Sil, therespective portions of the step portions 44, 46 are undercut or formedto provide for a tapered space or gap 58. Thus, the distal end `56 ofeach conductor may be dellected radially inwardly until the bottom ofthe gap 58 is engaged. It is therefore desirable for the conductor 5t)to be resilient such that when the deflecting force is removedtherefrom, it will spring back to the position shown in FIG. 6.

The female coupling element 24, shown in FIGS. 2b and 3 is constructedessentially the same as the male coupling portion 22, above described,with the exception that the step portions 44, 46 are formed within thebody of the element 24 thereby providing a socket configuration in theportion 34 adjacent end 28 rather than the plug conguration in theportion 32 aforedescribed. The step portions 44, 46 and the conductors58 are of substantially the same diameters and cross-sectional shapesand dimensions abovedescribed in reference to the male coupling element22, and conductors 50 are the same in number and are also spacedcircumferentially apart. The socket portion 34, shown in FIG. 2b,however, is of complementary size and shape to the plug portion 32 so asto mate therewith with the step portions 44, 46 of the socket portion 34in an overlapping manner. (See FIG. 5.) The distal ends S8 of theconductors 50 in the socket portion 34 are shaped to complement thedetent configuration 52, 54 of the plug portion 3-2 described above.Similarly, the step portions 44, 46 of the socket portion 34, whilesubstantially cylindrical, are shaped to complement the coniiguration ofthe same numbered step portions of the plug portion 32 so as tointimately lit together as shown in FIG. 5.

When the male coupling element 22 and the female coupling element 44 aretted together, the inner peripheral surfaces of the socket portion 34and the contacting surfaces of the elements 50 mate intimately andaxially overlie and engage the outer peripheral surfaces of the samenumbered step portions and conductors of the plug portion 32. Desirably,the diameters of the socket portion 34 are slightly smaller than thecompanion diameters of the plub portion 32 such that when the malecoupling element 22 and the female coupling element 24 are engaged, thedistal ends 58 of the conductors 5t) will be sprung radially inwardlyslightly so as to provide the intimate conductive contact necessarybetween elements 50 of the respective coupling elements 2.2, 24.

While the conductors 56 of the plug portion 32 can spring inwardlybecause of the relief 58 formed in the step portions 44, 46 adjacent end28 of the male coupling r element 22, still it is within the scope ofthis invention to relieve or taper the underside of the contacts 5t)beneath the distal end 56. Also the socket portion 34 may be formed withreliefs similar to the relief 58 (FIG. 6) for permitting such springingaction.

In a miniature or a microminiature version of the connector thus fardescribed, the conductors 50 are extremely small and may correspond insize to No. 34 copper wire. Obviously, if two ends of a wire of thissize were butted together, the contact resistance would be extremelyhigh as the area of contact would be relatively small. As is clearlyshown in FIG. 5, the male and female coupling elements 22, 24 do notabut in end-to-end relationship but instead the conductors 50 of theaforementioned elements overlap for a substantial distance so as toprovide a relatively large contact area. By virtue of the exing of theconductors 50 of the relatively long axial and overlapping lengths ofthe same, a contact resistance of a negligibly low value is obtained. Asis well known in the art, such low contact resistance in a miniaturizedconnector is an essential requirement in almost every case.

The detent shapes of the step portions 44, 46 are such as to permit theplug portion 32 and the socket portion 34 to be connected anddisconnected manually. The detent curvatures may be gradual andelongated as already shown and described or in the alternative may besharply pronounced and relatively short. Obviously, modifying the detentshapes of the plug portion 32 and the socket portion 34 will determinethe ease with which the coupling elements 22, 24 may be connected anddisconnected. Also, the degree of rigidity that the two couplingelements 22, 24 have when connected will be determined by the samedetent configuration. The principal purpose of the detent is to lock thetwo parts together, to resist separation thereof, and to create wipingaction between conductors thereby to minimize pitting corrosion ordeterioration thereof. While no means other than the detent has beenshown for accomplishing such locking purposes, still the conventionalscrew-type coupling may be added to the other portions on the couplingelements 22, 24 intermediate the ends 28, 30 for this purpose if atighter connection is desired.

Referring now to FIGS. 7 and 8 there is shown a second embodiment of themale and female coupling elements 22, 24. Both parts of this secondembodiment of the electrical connector of this invention are identicalin all respects as above described except for the method by which theconductors 50 are mounted and secured within the coupling elements 22,24. Referring to FIGS. 10 and 11, there is shown in perspective View,the conductors 50a and 50h which are used in the second ernbodiment ofthis invention. Conductor 50a is substantially of the same size,cross-sectional configuration and length as the conductor 50 used in thefirst embodiment and has the crest 52 and the valley 54 adjacent thedistal end 5.6 in the upper surface thereof, as aforedescribed. The onlydifference between the conductor 50a and the conductor 50 which wasaforedescribed in reference to the male coupling element 22 is thedetent 60 which is formed in the bottom surface of the conductor 50aadjacent but spaced apart from the end 62 opposite the distal end 58.Conductors 50cl are removably secured in the passageways 26 by means ofthis detent 60 and an annular groove 64 which is machined in both of thestep portions 38, 40 of both the coupling elements 22, 24 spaced fromthe distal ends 30, 39 respectively. More specifically, conductors 50aare slid through the previously formed passageways 26 until theconductors 50a positioned in the passageways 26 so that the detent 60will engage the groove 64. The resiliency of the conductor 50a holds thedetent 60 in passageway 64 thereby securing the same within thepassageway 26 until the end 62 of the conductor 50a is lifted therebyremoving the detent 60 from the groove 64. Similarly in all respects,the conductors 50h are positioned in the second embodiment of the femalecoupling element 24 illustrated in FIG. 8. Each conductor 50b has thecrest 52 and the valley 54 adjacent the distal end 58 in the bottomsurface thereof as distinguished from the conductor 50a. Conductors 58hare, however, identical to the conductors 5t) which are mounted in thefemale coupling element 24 in all respects except for detent 66 andtheir method of attachment.

The removable securance of the conductors 58a and 50b in the secondembodiment of the electrical coupling of this invention provides foreasy maintenance of the connector which is not possible with the firstembodiment. As the conductors 50, 50a, 50b are the portions of theelectrical connector receiving the wear and therefore likely todeteriorate with use or mishandling, by providing that the conductorsare replaceable, the life of the electrical connector may be prolongedindefinitely. Further, since the conductors may lose resiliency andtherefore not contact each other when in mating position over the entireexposed surface of the conductor, contact resistance may with ageincrease to a value that cannot be tolerated and therefore make theconductor useless as aforementioned. By the replacement of theappropriate conductors 50, 50a, 50h these maladies can be correctedeasily.

Referring now to FIGS. 9, 12 and 13, an apparatus and method formanufacturing the first embodiment of the electrical connectors of thisinvention will not be described. In FIGS. 12 and 13 there is showndiagrammatically an apparatus generally comprising a bin 70 containing aresin charge 72, a feeding mechanism 74, which can either be of thepiston type, the screw type or any similarly performing mechanism, andan elongated mold 76 having a plurality of core rods 78 extendingtherethrough and a cooling jacket surrounding the mold for a portion ofthe length of the mold 76. Bin 78 acts to funnel the resin charge 72into the feeding mechanism 74 which in turn leads into the mold 76.Cooling fluid is continually passed through the jacket 80 as indicatedby the arrows 82 to cool the surface of the mold 76. The core rods 78extended longitudinally of the mold 76 are capable of movement relativeto the mold 76 as indicated by the arrow 84. Mold 76 is preferablycylindrical in shape having an end closed by plate 86 and the oppositeopen; however, mold 76 can be square, round, rectangular or other shapeif desired. Movement of the core rods 78 may originate in a secondextrusion apparatus (not shown) by which the core rods 78 are formedjustp rior to entering the mold 76 through the companion clearanceapertures in the end plate 86 illustrated in FIG. 12.

FIG. 13 illustrates the specific configuration of the core rods 78 incross-section; however, other configurations may be used as desired. Asthe core rods 78 ultimately provide for the conductors 50 of thecoupling elements 22, 24, the core rods 78 can have cross-sectionalsizes and shapes such as those aforementioned and will becircumferentially spaced apart and arranged in a plurality of coaxialcircular sets.

The method of utilizing the apparatus illustrated in FIGS. 12 and 13 forfabricating the first embodiment of the electrical connector comprises afirst step of continuously feeding a resin charge 72 at a first rateinto the elongated mold 76 adjacent the end plate 86 by means of thefeeding mechanism 74. Secondly, the core rods 78 are continuously movedthrough said mold in the direction of arrow 84 at a second rate.Thirdly, coolant is passed through the jacket 80 as indicated by thearrow 82 to cool the mold intermediate the position 81, at which theresin charge enters the mold 76, and the open end of the mold 76 so asto solidify the resin charge adjacent the open end. The resin chargeenters the mold 76 at a third rate. Fourthly, the first, second andthird rates are controlled so that the resin charge remains plastic fora sufficient length of time to fill completely the mold 76 between theend plate 86 and a solidified portion of the resin adjacent the open endof mold 76 (not shown) to eliminate all bubbles and other voids in theplastic resin charge before the resin charge solidies. Thesolidiiication of the resin charge must also be at a rate so that itwill secure to the core rods 78 and move therewith through the mold 76at the same rate as the core rods 78. Fifthly, a solidified resin chargeis continuously extracted from the mold 76 in the form of a rod ofinsulating material with a plurality of core rods secured therein. As asixth step, this rod is cut into segments having opposite ends and thedesired length. Such a rod segment is illustrated in FIG. 9 andindicated by the numeral 83. As shown, the core rods 78 and thesolidified resin form an integral structure. Rod segments 83 are thenplaced in a lathe, a screw machine or similar device, and as a seventhstep, one of the ends of each rod segment 83 is turned to form aplurality of coaxially cylindrical steps, such as 38, 40, and therebyexpose the surface of the core rods 78 to provide a surface onto whichwires may be soldered or welded as above described. As an eighth step,the opposite end of each rod segment is turned in similar fashion toform either a male or a female coupling portion 32 or 34, respectively,having a plurality of step portions which are equal in number to thenumber of coaxial and cylindrical step portions of the opposite end. Thenumber of step portions at both ends is determined by the number ofcoaxial sets in which the core rods 78 are arranged. This second turningoperation also forms the detent configurations 52, 54, 56 of the stepportions of the coupling portions 32, 34. The final step comprisesforming a cavity such as that indicated by numeral 58 (FIG. 6) by meansof a drilling, boring or a similar operation under each of the core rods'78 adjacent to the distal ends of the plug and socket portions 32, 34.As is above obvious, the core rods 78 must be formed of conductingmaterial, preferably one of these materials mentioned above, and theresin charge must form an insulating material after solidification,preferably one of those plastic materials abovementioned and described.

Referring now to FIGS. 14 and 15, an apparatus for performing a methodof fabricating the second embodiment of electrical connectors of thisinvention is diagrammatically illustrated. In many respects this secondapparatus is similar to that shown in FIGS. 12 and 13 as indicated bythe like reference numerals that have been assigned to like parts.Generally, the only ditference in the apparatus for performing thesecond method of this invention from that shown in FIGS. 12 and 13 isthat the cooling jacket 80 extends substantially the entire length ofthe mold 76. Similarly to FIG. 13, FIG. 15 shows in cross-section aconfiguration of the core rods 78 in an arrangement of coaxial setscircumferentially and equally spaced apart. Further, this second methodof this invention is identical to the first method except that the corerods remain stationary and the apparatus extrudes a rod of insulatingmaterial having passageways 26 extending therethrough rather than thecore rods 78 above-mentioned. In this second method, the rst rate ofcharging the resin into the mold 76 and the rate of cooling the mold 76by means of the jacket 80 need only be controlled relative to each otherto provide that the mold 76 is adequately filled without voids. Theextruded rod is also extracted from the mold 76 and cut into segments ofdesired length and turned at the opposite ends thereof in identicalmanner to that above-described. However, during the turning operationwhich forms the step portions at the terminal end 30 of both the maleand female coupling elements 22, 24, the annular grooves 64 are alsoformed. The conductors 50a and Stib are thereafter inserted through thepassageway 26 in a final assembling step resulting in coupling elements22, 24 as illustrated in FIGS. 7 and 8 and above-described.

In operation, since the actual area of contact of each individualconductor 50 as shown in the drawings is arcuate, it is apparent that amuch greater area of actual contact between mated male and femalecoupling elements 22, 2d prevails over other known connector concepts.Because of the unique method of insuring intimate engagement between themale and female coupling elements, even though a connector assembly maycontain a relatively large number of conductors, proper electricalconnection between the respective male and female contacts is alwaysassured.

Of extreme value in this direction is the fact that the conductors 5t),Stia, Stlb are protected on the bottoms and sides thereof by theconnector portions 44, 46. If the connector part should be dropped, thechances are quite remote that the conductors 50 will be bent. Since suchcontacts in the miniature connectors are extremely small, correspondingto No. 34 gauge wire or gauges even smaller than this, it is obviousthat a slight bump or touching with another object can bend a conductor50. However, in the design of this invention, the conductor 50 isprotected on three sides by the step portions 44, 46 such that roughhandling or bumping of the conductors 50 can be tolerated without anymaterial danger of producing any damage. If such damage should occur,the second embodiment of this electrical connector permits theindividual conductors to be replaced. Thus, the rnale and female partsof the electrical connector assembly of this invention can be reliablyconnected and disconnected :many times with full and complete assurancethat all of the conductors will properly mate. Further, periodicreplacement of the conductors Stia and 50]; of the second embodiment ofthe electrical connector of this invention will assure satisfactoryperformance of the connector for an indefinite period.

Statistics within the industry support the fact that a considerablepercentage of existing problems associated with connectors andterminations are a result of damaged conductors which this concept, asdisclosed, avoids.

While the coupling elements 22, 24 are described herein to have terminalends 30 and plug and socket portions 32, 34, respectively, at theopposite end 2S, it is within the scope of this invention to provide amale coupling having plug portions 32 adjacent ends 28, 30 or a femalecoupling having socket portions 34 adjacent ends 28, 30. It is furtherwithin the scope of this invention to provide a spacer having a plugportion 32 adjacent end 28 and a socket portion 34 adjacent end 30.

While there have been described above the principles of this inventionin connection with specific apparatus, it is to be clearly understoodthat this description is made only by way of example and not as alimitation to the scope of the invention.

What is claimed is:

1. A method of fabricating connector parts comprising the steps ofcontinuously feeding at a first rate a resin charge into an elongatedand cylindrical mold having an open end, an opposite closed end, and aplurality of axially extending core rods arranged in a plurality ofcoaxial circular sets and in parallelism with each other, said core rodsin each set being spaced circumferentially equally apart, said chargeentering said mold at a position adjacent said closed end, cooling saidresin charge intermediate said position and said open end at a secondrate thereby to solidify said resin charge adjacent to said open end,controlling said first and second rates so that said resin chargeremains plastic for a time sufficient to till said mold before saidresin charge solidifies, continuously extracting the solidified chargefrom said mold as a rod of insulating material, cutting said rod intosegments having opposite ends and a predetermined length, turning one ofsaid ends of each of said-segments thereby to form a plurality ofcoaxial cylindrical steps equal in number to said sets, and turning theother of said ends of each of said segments thereby to form an equalnumber of coaxial cylindrical steps as said one end.

2. The method of claim 1 wherein said core rods are conductors and arecontinuously being fed through said mold and extracted with saidsolidified charge.

3. A method of fabricating connector parts comprising the steps ofcontinuously feeding at a first rate a resin charge into an elongatedand cylindrical mold having an open end, an opposite closed end, and aplurality of axially extending core rods arranged in a plurality ofcoaxial circular sets and in parallelism with each other, said core rodsin each set being spaced circumferentially equally apart, said chargeentering said mold at a position adjacent said closed end, cooling saidresin charge intermediate said position and said open end at a secondrate thereby to solidify said resin charge adjacent to said open end,controlling said first and second rates so that said resin chargeremains plastic for a time sufficient to ll said mold before said resincharge solidies, continuously extracting the solidified charge from saidmold as a rod of insulating material, cutting said rod into segmentshaving opposite ends and a predetermined length, turning one of saidends of each of said segments thereby to form a rst stepped diameter endon said segments having a plurality of first cylindrical step portionsequal in number to said sets, and turning the other of said ends of eachof said segments thereby to form a second stepped diameter end on saidsegments having a plurality of second cylindrical step portions equal innumber to said rst step portions, each of said rst and second stepportions having radially outwardly facing surfaces.

4. A method of fabricating connector parts comprising the steps ofcontinuously feeding at a first rate a resin charge into an elongatedand cylindrical mold having an open end, an opposite closed end, and aplurality of axially extending core rods arranged in a plurality ofcoaxial circular sets and in parallelism with each other, said core rodsin each set being spaced circumferentially equally apart, said chargeentering said mold at a position adjacent said closed end, cooling saidresin charge intermediate said position and said open end at a secondrate thereby to solidify said resin charge adjacent to said open end,controlling said first and second rates so that said resin chargeremains plastic for a time sufficient to fill said mold before saidresin charge solidifies, continuously exltracting the solidified chargefrom said Imold as a rod of insulating material, cutting said rod intosegments having opposite ends and a predetermined length, turning one ofsaid ends of each of said segments thereby to form a first steppeddiameter end on said segments having a plurality of first cylindricalstep portions equal in number .to said sets, and turning the other ofsaid ends of each of said segments thereby to form `a second steppeddiameter end on said segments having a plurality of second cylindricalstep portions equal in number to said first step portions, each of saidfirst and second step portions having radially inwardly facing surfaces.

5. A method of fabricating connector parts comprising the steps ofcontinuously extruding a rod of insulating material, continuouslyforming a plurality of passages in said rod as it is being extruded,cutting the rod into segments having opposite ends and the desiredlength, turning one of said ends of each of said segments an amountsufficient to penetrate the cross-sections of predetermined ones of saidpassages to expose longitudinal end portions thereof, thereby to form atleast one exterior and coaxial cylindrical step, and turning the otherof said ends of said segments thereby to form an equal number of coaxialcylindrical steps as said one end.

6. A method of fabricating connector parts comprising the steps ofcontinuously feeding at a first rate a resin charge into an elongatedand cylindrical mold having an open end, an opposite closed end, and aplurality of axially extending core rods arranged in a plurality ofcoaxial circular sets and in parallelism with each other, said core rodsin each set being spaced circumferentially equally apart, said chargeentering said mold at a position adjacent to said closed end, coolingsaid mold intermediate said position and said open end at a second ratethereby to solidify said resin charge adjacent to said open end,controlling said first and second rates so that said resin chargeremains plastic for a time sufficient to fill said mold before saidresin charge solidifies, continuously extracting the solidified resincharge from said mold as a rod of insulating material, said rod having aplurality of longitudinal and parallel passageways therein formed bysaid core rods, cutting said rod into segments having opposite ends andthe desired length, turning one of said ends of said segments to form anannular detent groove spaced from said one end and a plurality ofexterior and coaxial cylindrical steps which communicate with saidpassageways and are equal in number to said sets, turning the other ofsaid ends of said segments thereby to form an equal number of coaxialcylindrical steps as said one end, and positioning conductors having adetent thereon in said passageways with said detent in said groove.

7. A method of fabricating connector parts comprising the steps ofcontinuously feeding at a first rate a resin charge into an elongatedand cylindrical mold having an open end, an opposite closed end, and aplurality of axially extending core rods arranged in a plurality ofcoaxial circular sets and in parallelism with each other, said core rodsin each set being spaced circumferentially equally apart, said chargeentering said mold at a position adjacent to said closed end, coolingsaid mold intermediate said position and said open end at a second ratethereby to solidify said resin charge adjacent to said open end,controlling said first and second rates so that said resin chargeremains plastic for a time sufficient to fi11 said mold before saidresin charge solidifies, continuously extracting the solidified resincharge from said mold as a rod of insulating material, said rod having aplurality of longitudinal and parallel passageways therein formed bysaid core rods, cutting said rod into segments having opposite ends andthe desired length, turning one of said ends of said segments to form anannular detent groove spaced from said one end and a plurality of firstcoaxial cylindrical step portions which are equal in number to said setsand which communicate with said passageways, turning the other of saidends of each of said segments thereby to form an equal number of secondcoaxial and cylindrical step portions as said one end, said second stepportions having radially outwardly facing surfaces, and positioningconductors having a detent thereon in said passageways with said detentin said groove.

8. A method of fabricating connector parts comprising the steps ofcontinuously feeding at a first rate a resin charge into an elongatedand cylindrical mold having an open end, an opposite closed end, and aplurality of axially extending core rods arranged in a plurality ofcoaxial circular sets and in parallelism with each other, said core rodsin each set being spaced circumferentially equally apart, said chargeentering said mold at a position adjacent to said closed end, coolingsaid mold intermediate said position and said open end at a second ratethereby to solidify said resin charge adjacent to said open end,controlling said first and second rates so that said resin chargeremains plastic for a time sufficient to fill said mold before saidresin charge solidifies, continuously extracting the solidified resincharge from said mold as a rod of insulating material, said rod having aplurality of longitudinal and parallel passageways therein formed bysaid core rods, cutting said rod into segments having opposite ends andthe desired length, turning one of said ends of said segments to form anannular detent groove spaced from said one end and a plurality of firstcoaxial cylindrical step portions which are equal in number to said setsand which communicate with said passageways, lturning the other of saidends of each of said segments thereby to form an equal number of secondcoaxial and cylindrical step portions as said one end, said second stepportions having radially inwardly facing surfaces, and positioningconductors having a detent thereon in said passageways with said detentin said groove.

9. A method of fabricating connector parts comprising the steps ofcontinuously feeding at a first rate a resin charge into an elongatedand cylindrical mold having an open end, an opposite closed end, and -aplurality of axially extending core rods arranged in a plurality ofcoaxial circular sets and in parallelism with each other, said core rodsin each set being spaced circumferentially equally apart, said chargeentering said mold at a position adjacent to said closed end,continuously moving said core rods through said mold at a second rate,cooling said mold intermediate said position and said open end at athird rate thereby to solidify said resin charge adjacent said open end,controlling said first, second, and third rates so that said resincharge remains plastic for a time sufiicient to fill said mold beforesaid resin charge solidifies and said resin charge solidifies at a rateso that said resin charge secures to said core rods and moves throughsaid mold at the same rate as said core rods, continuously extractingthe solidified resin charge and said core rods from said mold as a rodof insulating material with said core rods being secured in said rod,cutting said rod into segments having opposite ends and the desiredlength, turning one of said ends of said segments to form a plurality ofcoaxial cylindrical steps which communicate with said core rods and areequal in number to said sets, turning the other of said ends of saidsegments thereby to form an equal number of coaxial cylindrical steps assaid one end, and forming a cavity under each core rod adjacent to saidother end.

10. A method of fabricating connector parts comprising the steps ofcontinuously feeding at a first rate a resin charge into an elongatedand cylindrical mold having an open end, an opposite closed end, and aplurality of axially extending core rods arranged in a plurality ofcoaxial circular sets and in parallelism with each other, said core rodsin each set being spaced circumferentially equally apart, said chargeentering said mold at a position adjacent to said closed end,continuously moving said core rods through said mold at a second rate,cooling said mold intermediate said position and said open end at athird rate thereby to solidify said resin charge adjacent said open end,controlling said first, second, and third rates so that said resincharge remains plastic for a time sufficient to fill said mold beforesaid resin charge solidiiies and said resin charge solidiiies at a rateso that said resin charge secures to said core rods and moves throughsaid mold at the same rate as said core rods, continuously extractingthe solidified resin charge and said core rods from said mold as a rodof insulating material with said core rods being secured in said rod,cutting said rod into segments having opposite ends and the desiredlength, turning one of said ends of each of said segments to form aplurality of first coaxial cylindrical step portions Which communicatewith said core rods and are equal in number to said sets, turning theother of said ends of each of said segments thereby to form an equalnumber of second coaxial and cylindrical step portions as said one end,said second step portions having radially outwardly facing surfaces, andforming a cavity under each core rod adjacent to said other end.

11. A method of fabricating connector parts comprising the steps ofcontinuously feeding at a first rate a resin charge into an elongatedand cylindrical mold having an open end, an opposite closed end, and aplurality of axially extending core rods arranged in a plurality ofcoaxial circular sets and in parallelism with each other, said core rodsin each set being spaced circumferentially equally apart, said chargeentering said mold at a position adjacent to said closed end,continuously moving said core rods through said mold 'at a second rate,cooling said mold intermediate said position and said open end at athird rate thereby to solidify said resin charge adjacent said open end,controlling said first, second, and third rates so that said resincharge remains plastic for a time suiiicient to ll said mold before saidresin charge solidifies and said resin charge solidilies at a rate sothat said resin charge secures to said core rods and moves through saidmold at the same rate as said core rods, continuously extracting thesolidified resin charge and said core rods from said mold as a rod ofinsulating material with said core rods being secured in said rod,cutting said rod into segments having opposite ends and the desiredlength, turning one of said ends of each of said segments to form aplurality of first coaxial cylindrical step portions which communicatewith said core rods and are equal in number to said sets, turning theother of said ends of each of said segments thereby to form an equalnumber of second coaxial and cylindrical step portions as said one end,said second step portions having radially inwardly facing surfaces, andforming a cavity under each core rod adjacent to said other end.

12. A method of fabricating connector parts comprising the steps ofcontinuously feeding a resin charge into van elongated mold having anopen end, an opposite closed end, and a plurality of spaced-apart corerods arranged longitudinally of said mold and in parallelism with eachother, solidifying said resin adjacent said open end, continuouslyextracting the solidified resin charge from said mold as a rod ofinsulating material having axial extending passageways formed by saidcore rods, cutting said rod into segments having opposite ends and thedesired length, exposing an axially extending portion of saidpassageways adjacent to one of said ends of said segments, andsubstituting conductors for said core rods.

13. A method of fabricating connector parts comprising the steps ofcontinuously feeding a resin charge into an elongated mold having anopen end, an opposite closed end, and a plurality of spaced-apart corerods arranged longitudinally of said mold and in parallelism with eachother, said core rods being conductive, continuously moving said corerods through said mold, solidifying said resin adjacent to said open endas a rod of insulating material having said core rods secured therein,continuously extracting said rod and said core rods from said mold,cutting said rod into segments having opposite ends and the desiredlength, exposing an axially extending portion of said core rods adjacentto one of said ends of said segments and forming a cavity under eachcore rod adjacent said one end.

14. A method of fabricating connector parts comprising the steps ofcontinuously extruding a rod of insulating material, continuouslyforming a plurality of passages in said rod as it is being extruded,cutting the rod into Segments having opposite ends and the desiredlength, and turning one of said ends of each of said segments an amountsuflicient to penetrate the cross-sections of predetermined ones of saidpassages to expose longitudinal end portions thereof, thereby to form atleast one coaxial cylindrical step.

15. A method of fabricating connector parts comprising the steps offeeding at a lirst rate a resin charge into an elongated mold having anopen end, an opposite closed end, and a plurality of axially extendingcore rods arranged in at least one coaxial circular set, said core rodsin said at least one set being parallel to each other and spacedcircumferentially apart, said charge entering said mold at a positionadjacent said closed end, cooling said resin charge intermediate saidposition and said open end lat a second rate thereby to solidify saidresin charge adjacent to said open end, controlling said first andsecond rates so that said resin charge remains plastic for a timesutiicient to fill said mold before said resin charge solidifies,extracting the solidified charge from said mold as -a rod of insulatingmaterial, cutting said rod into segments having opposite ends and apredetermined length, turning one of said ends of each of said segmentsthereby to form at least one coaxial cylindrical step equal in number tosaid at least one set thereby exposing said at least one set.

References Cited UNITED STATES PATENTS 2,749,526 6/1956 Petersen 339-613,118,713 1/1964 Ellis 339-176 X 3,218,599 11/1965 Winkler 29-155.55 X3,229,137 1/1966 McCarty 29-155.53 X 3,235,832 2/1966 Buchanan et al.339-176 3,333,232 7/1967 Patton 339-182 JOHN F. CAMPBELL, PrimaryExaminer.

C. E. HALL, Assistant Examiner.

U.S. Cl. XR.

